src/gallium/drivers/r600/sb/sb_psi_ops.cpp

   1 /*
   2  * Copyright 2013 Vadim Girlin <vadimgirlin@gmail.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * on the rights to use, copy, modify, merge, publish, distribute, sub
   8  * license, and/or sell copies of the Software, and to permit persons to whom
   9  * the Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  21  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *      Vadim Girlin
  25  */
  26
  27 #include "sb_shader.h"
  28
  29 #include "sb_pass.h"
  30
  31 namespace r600_sb {
  32
  33 bool r600_sb::psi_ops::visit(alu_node& n, bool enter) {
  34         if (enter) {
  35         }
  36         return false;
  37 }
  38
  39 bool psi_ops::visit(node& n, bool enter) {
  40         if (enter) {
  41                 assert(n.subtype == NST_PSI);
  42
  43                 try_inline(n);
  44
  45                 // TODO eliminate predication until there is full support in all passes
  46                 // unpredicate instructions and replace psi-nodes with conditional moves
  47                 eliminate(n);
  48         }
  49         return false;
  50 }
  51
  52 value* get_pred_val(node &n) {
  53         value *pred_val = NULL;
  54
  55         for (vvec::iterator I = n.src.begin(), E = n.src.end(); I != E; I += 3) {
  56                 value* &pred = *I;
  57                 if (pred) {
  58                         if (!pred_val)
  59                                 pred_val = pred;
  60                         else {
  61                                 assert(pred == pred_val);
  62                         }
  63                 }
  64         }
  65         return pred_val;
  66 }
  67
  68 // for now we'll never inline psi's with different predicate values,
  69 // so psi node may only contain the refs to one predicate value.
  70 bool psi_ops::try_inline(node& n) {
  71         assert(n.subtype == NST_PSI);
  72
  73         vvec &ns = n.src;
  74
  75         int sz = ns.size();
  76         assert(sz && (sz % 3 == 0));
  77
  78         value *pred_val = get_pred_val(n);
  79
  80         int ps_mask = 0;
  81
  82         bool r = false;
  83
  84         for (int i = sz - 1; i >= 0; i -= 3) {
  85
  86                 if (ps_mask == 3) {
  87                         ns.erase(ns.begin(), ns.begin() + i + 1);
  88                         return r;
  89                 }
  90
  91                 value* val = ns[i];
  92                 value* predsel = ns[i-1];
  93                 int ps = !predsel ? 3 : predsel == sh.get_pred_sel(0) ? 1 : 2;
  94
  95                 assert(val->def);
  96
  97                 if (val->def->subtype == NST_PSI && ps == 3) {
  98                         if (get_pred_val(*val->def) != pred_val)
  99                                 continue;
 100
 101                         vvec &ds = val->def->src;
 102
 103                         ns.insert(ns.begin() + i + 1, ds.begin(), ds.end());
 104                         ns.erase(ns.begin() + i - 2, ns.begin() + i + 1);
 105                         i += ds.size();
 106                         r = true;
 107
 108                 } else {
 109                         if ((ps_mask & ps) == ps) {
 110                                 // this predicate select is subsumed by already handled ops
 111                                 ns.erase(ns.begin() + i - 2, ns.begin() + i + 1);
 112                         } else {
 113                                 ps_mask |= ps;
 114                         }
 115                 }
 116         }
 117         return r;
 118 }
 119
 120 bool psi_ops::try_reduce(node& n) {
 121         assert(n.subtype == NST_PSI);
 122         assert(n.src.size() % 3 == 0);
 123
 124         // TODO
 125
 126         return false;
 127 }
 128
 129 void psi_ops::unpredicate(node *n) {
 130
 131         if (!n->is_alu_inst())
 132                 return;
 133
 134         alu_node *a = static_cast<alu_node*>(n);
 135         a->pred = NULL;
 136 }
 137
 138 bool psi_ops::eliminate(node& n) {
 139         assert(n.subtype == NST_PSI);
 140         assert(n.src.size() == 6);
 141
 142         value *d = n.dst[0];
 143
 144         value *s1 = n.src[2];
 145         value *s2 = n.src[5];
 146
 147         value *pred = n.src[3];
 148
 149         bool psel = n.src[4] == sh.get_pred_sel(0);
 150
 151         value *sel = get_select_value_for_em(sh, pred);
 152
 153         if (s1->is_undef()) {
 154                 if (s2->is_undef()) {
 155
 156                 } else {
 157                         n.insert_after(sh.create_mov(d, s2));
 158                 }
 159         } else if (s2->is_undef()) {
 160                 n.insert_after(sh.create_mov(d, s1));
 161         } else {
 162                 alu_node *a = sh.create_alu();
 163                 a->bc.set_op(ALU_OP3_CNDE_INT);
 164
 165                 a->dst.push_back(d);
 166                 a->src.push_back(sel);
 167
 168                 if (psel) {
 169                         a->src.push_back(s1);
 170                         a->src.push_back(s2);
 171                 } else {
 172                         a->src.push_back(s2);
 173                         a->src.push_back(s1);
 174                 }
 175
 176                 n.insert_after(a);
 177         }
 178
 179         n.remove();
 180
 181         if (s1->is_any_gpr() && !s1->is_undef() && s1->def)
 182                 unpredicate(s1->def);
 183         if (s2->is_any_gpr() && !s2->is_undef() && s2->def)
 184                 unpredicate(s2->def);
 185
 186         return false;
 187 }
 188
 189 } // namespace r600_sb